What is the proprer tension for the rear belt drive. I know that a certain range of motion in the slack is some number. But what is that number?

Nurple,
Bottom belt deflection for the 883 and 1200 customs should be 1/4th - 5/16th in. (6.5 - 7.9mm). The 883 standard and 1200 Roadster models should be 3/8th - 7/16th in. (9.5 - 11.1mm)

The owners manuel recommends the use of a Belt Tension Gauge (part # HD-35381) to apply 10lbs of force at the midpoint af the bottom belt strand. This should be done while a rider is sitting on the bike.

On some models, there is a black plastic lower belt guard that has a verticle slot. The slot is for the purpose of guaging the tension. I guess I would question how accurate that really is!
Billy

The numbers I quoted are out of the 2004 owners manuel, so if your bike is earlier than that, those numbers may very well be different!
Billy

Thanks! It is an 86 xl with the conversion (1340cc), and slammed 3" to the ground. The original chain was swapped out for an 1 1/8" belt. Not sure what the slack should be, because 86 manual is for a chain....